Removal of surface passivation

ABSTRACT

Methods for removing a passivation film from a copper surface can include exposing the passivation film to a vapor phase organic reactant, for example at a temperature of 100° C. to 400° C. In some embodiments, the passivation film may have been formed by exposure of the copper surface to benzotriazole, such as can occur during a chemical mechanical planarization process. The methods can be performed as part of a process for integrated circuit fabrication. A second material can be selectively deposited on the cleaned copper surface relative to another surface of the substrate.

REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. application Ser. No.14/628,799 filed Feb. 23, 2015, each of which is hereby incorporated byreference in its entirety.

BACKGROUND

Field

The present disclosure relates generally to the field of semiconductordevice manufacturing and, more particularly, to removal of surfacepassivation such as from a copper layer following chemical mechanicalplanarization processes.

Description of the Related Art

Electrical interconnects in electronic devices often comprise copper(Cu), due to the resistivity, frequency capability, power requirementand/or electromigration performances of copper. For example,three-dimensional structures can be formed in dielectric material on asubstrate surface (e.g., trench and/or via structures). Copper can besubsequently deposited over and/or within the three-dimensionalstructures to form the desired electrical interconnects.

Chemical mechanical planarization (CMP) is typically used for etchingback excess copper on a substrate surface, as patterning of copper usingreactive ion etching (RIE) may be challenging due to difficulty in theformation of volatile copper-containing byproducts. Chemical mechanicalplanarization can be used to remove excess copper from the substratesurface (e.g., copper deposited over the substrate surface for formingelectrical interconnects) and/or to planarize copper on the substratesurface to prepare the substrate surface for subsequent processing.Chemical mechanical planarization can utilize a combination of chemicaland mechanical forces in its removal of material from the substratesurface. For example, chemical mechanical planarization typically uses apolishing pad to apply a slurry solution to a substrate surface for etchback and planarization of the substrate surface. However, exposure ofcopper to the slurry solution during the chemical mechanicalplanarization process may result in formation of a passivation film onthe substrate surface over the copper. While the passivation film mayprevent oxidation of the underlying copper, for example due to exposureof the copper to oxygen-containing ambient during transport of thesubstrate during processing, the passivation film may undesirably modifyone or more characteristics of the substrate surface for subsequentprocessing.

Use of a plasma process in removal of the passivation film mayundesirably modify one or more characteristics of the copper surface.Plasma processes may damage the copper surface, generate contaminantswithin the reaction space, and/or undesirably modify surfacecharacteristics of one or more other materials on the substrate surface(e.g., a dielectric material, such as a low-k dielectric material).Controlled exposure of the substrate surface to reactants in removalprocesses that utilize liquid phase reactants may be difficult. Use ofliquid phase reactants may also contribute to reduced throughput, forexample due to an additional drying process that is required afterremoval of the passivation material. Additionally, liquid phasereactants may undesirably penetrate pores of porous low-k materials,contributing to degradation of the low-k materials.

Therefore, a continued need exists for improved methods of removingsurface passivation material formed over copper.

SUMMARY

In some aspects, methods for removing passivation material from asubstrate are provided. In some embodiments, methods for removing apassivation film from a substrate can include providing a substrateincluding the passivation film on a metal surface. The passivation filmmay have been formed by exposure of the metal surface to a passivationagent including a hydrocarbon. The passivation film is exposed to avapor phase organic reactant, for example at a temperature of about 100°C. to about 400° C. In some embodiments, the passivation film is notexposed to a plasma during exposure of the passivation film to the vaporphase organic reactant.

In some embodiments, the metal surface is a copper surface. In someembodiments, the substrate can include a dielectric material, and asurface chemistry of the dielectric material is substantially unaffectedby exposing the passivation film to the vapor phase organic reactant. Insome embodiments, exposing the passivation film to the vapor phaseorganic reactant can be repeated at least 10 times.

In some embodiments, methods of removing a passivation film from asubstrate surface can include exposing the passivation film to a vaporphase organic reactant that includes carboxylic acid. In someembodiments, the vapor phase organic reactant can include formic acid.In some embodiments, the passivation agent can include an aromatichydrocarbon. In some embodiments, the passivation agent that forms thepassivation film can include benzotriazole.

In some aspects, methods for integrated circuit fabrication areprovided. Methods for integrated circuit fabrication can includeproviding a substrate including a passivation film on a copper surface.The passivation film may have been formed by subjecting a copper surfaceof the substrate to a chemical mechanical planarization process. Acleaning process can be carried out for removing the passivation filmfrom the copper surface. Performing the cleaning process can includecontacting the passivation film with a vapor phase organic reactant, forexample at a process temperature of about 100° C. to about 400° C. Insome embodiments the vapor phase organic reactant has the formulaR—COOH, the R being a hydrogen, or a C1-C3 alkyl. The vapor phaseorganic reactant may be formic acid. In some embodiments the cleaningprocess is substantially free of plasma activated reactants. In someembodiments, the process temperature is about 200° C. to about 250° C.

In some embodiments, the chemical mechanical planarization process caninclude exposing the copper surface to a passivation agent to form thepassivation film, where the passivation agent can include benzotriazole.

In some embodiments, the substrate can include a dielectric material,and a surface chemistry of the dielectric material may be substantiallyunaffected by the cleaning process.

In some aspects, methods of integrated circuit fabrication can includecleaning a copper surface of a substrate by removing a passivation filmthat was formed on the copper surface by exposure to a hydrocarbonpassivation agent. Cleaning can include contacting the passivation filmwith a vapor phase organic reactant substantially without exposing thesubstrate to a plasma. A second material can be selectively deposited onthe cleaned copper surface relative to a second surface on thesubstrate. The passivation film may be removed at a process temperatureof about 100° C. to about 400° C.

In some embodiments, the passivation film can include a coordinationcomplex formed by the copper and the passivation agent. In someembodiments, the passivation agent can include benzotriazole and thevapor phase organic reactant can include a carboxylic acid.

In some embodiments, the second material can include an electricallyconductive material. For example, the second material can includetungsten. In some embodiments, the second material can include anelectrically insulating material. In some embodiments, the secondsurface can include a dielectric material, and the second material isselectively deposited on the cleaned surface relative to the dielectricmaterial. In some embodiments the second material is substantially notdeposited on the dielectric material.

For purposes of summarizing the invention and the advantages achievedover the prior art, certain objects and advantages are described herein.Of course, it is to be understood that not necessarily all such objectsor advantages need to be achieved in accordance with any particularembodiment. Thus, for example, those skilled in the art will recognizethat the invention may be embodied or carried out in a manner that canachieve or optimize one advantage or a group of advantages withoutnecessarily achieving other objects or advantages.

All of these embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments will becomereadily apparent to those skilled in the art from the following detaileddescription having reference to the attached figures, the invention notbeing limited to any particular disclosed embodiment(s).

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure are described with reference to the drawings of certainembodiments, which are intended to illustrate certain embodiments andnot to limit the invention.

FIG. 1 shows an example of a substrate surface cleaning process forremoving a passivation film formed over a copper layer.

FIG. 2 shows another example of a substrate surface cleaning process forremoving a passivation film formed over a copper layer.

DETAILED DESCRIPTION

Although certain embodiments and examples are described below, those ofskill in the art will appreciate that the invention extends beyond thespecifically disclosed embodiments and/or uses and obvious modificationsand equivalents thereof. Thus, it is intended that the scope of theinvention herein disclosed should not be limited by any particularembodiments described below.

In some embodiments, methods are provided for removing a passivationmaterial from a substrate. In some embodiments a substrate is providedcomprising a passivation film on a metal surface, such as a copper (Cu)surface, a nickel (Ni) surface, or a cobalt (Co) surface. In someembodiments, a passivation film may be formed or have previously beenformed on a copper-containing surface, a nickel-containing surface, or acobalt-containing surface. In some embodiments, the passivation film maybe formed when a passivation agent forms a coordination bond with thecopper, nickel or cobalt. For example, the passivation film may beformed on a substrate surface when a passivation agent forms acoordination complex with the copper (Cu), nickel (Ni) or cobalt (Co) onthe substrate surface. In some embodiments, the passivation film may bea continuous or substantially continuous film. However, althoughgenerally referred to herein as a passivation film, in some embodiments,the passivation material may not form a complete, or uninterrupted filmover the metal surface. For example in some embodiments a passivationfilm may cover only one or more portions of a metal surface, and not theentire metal surface. In some embodiments a passivation film maycomprise one or more discontinuous areas of a passivation material on ametal surface. The passivation film referred to herein may comprise amaterial which can reduce or prevent further oxidation of the metalsurface on which it is formed.

In some embodiments, a passivation agent may be a chemical thatcoordinates to copper, nickel or cobalt. In some embodiments thepassivation agent may be a complexing agent that forms a coordinationcomplex with copper nickel or cobalt. In some embodiments a passivationagent may comprise a hydrocarbon. In some embodiments, the passivationagent may comprise a cyclic hydrocarbon, for example an aromatichydrocarbon.

In some embodiments, the passivation agent may comprise a carbon atom(C), a hydrogen atom (H) and a nitrogen atom (N) or sulfur atom (S). Forexample, the passivation agent may comprise a cyclic hydrocarboncomprising carbon, hydrogen and nitrogen. In some embodiments thepassivation agent may comprise an aromatic hydrocarbon comprisingcarbon, hydrogen and nitrogen.

In some embodiments, the passivation agent may comprise a carbon atom, ahydrogen atom and a nitrogen atom. For example, the passivation agentmay be a hydrocarbon comprising carbon, hydrogen and nitrogen. In someembodiments the passivation agent may comprise a carbon atom, a hydrogenatom and at least two nitrogen atoms. In some embodiments, thepassivation agent can comprise at least three nitrogen atoms. Forexample, the passivation agent may comprise a carbon atom, a hydrogenatom and at least three nitrogen atoms.

In some embodiments, the passivation agent may comprise sulfur. Forexample, a passivation agent may comprise a carbon atom, a hydrogen atomand a sulfur atom.

In some embodiments, a passivation agent may form a coordination bondwith copper, nickel or cobalt on a substrate surface through one or morenitrogen atoms. In some embodiments the passivation agent coordinatescopper through at least one nitrogen atom and in some embodimentsthrough at least two nitrogen atoms. For example, a passivation agentcomprising carbon, hydrogen and two nitrogen atoms may coordinate withcopper on a substrate surface through one of the nitrogen atoms, or bothof the nitrogen atoms.

In some embodiments, the passivation agent for forming a passivationfilm on a copper surface may comprise benzotriazole (BTA).

Although discussed herein primarily in terms of BTA as a passivationagent on a Cu surface, unless indicated otherwise, other passivationagents as described herein can be substituted for BTA and Ni or Cosurfaces may be substituted for the Cu surface.

In some embodiments, the passivation film may be formed on a coppersurface (or Ni or Co) of the substrate, such as by exposure of thesurface to BTA (or another passivation agent) during a chemicalmechanical planarization process. In particular, in some embodiments apassivation film formed on a copper (or Ni or Co) surface due toexposure of the surface to BTA or another passivation agent can beremoved using a vapor phase organic reactant.

In some embodiments, the vapor phase organic reactant comprises formicacid. For example, exposing the passivation film to vapor phase formicacid may result in formation of one or more volatile byproducts, therebyfacilitating removal of the passivation film from the copper surface. Insome embodiments, removing the passivation film comprises exposing thepassivation film to a plurality of pulses of vapor phase formic acid.

A substrate surface may comprise copper, such as copper deposited on thesubstrate surface for electrical interconnect. In some embodiments thesubstrate surface may comprise Ni or Co. The substrate surface may alsocomprise one or more other materials, such as a dielectric material. Forexample, the substrate surface may comprise a low-k dielectric material(e.g., extreme low-k material (ELK), such as dielectric material havinga dielectric constant (k) of about 2.3). Copper may be deposited overand/or within three-dimensional features on the substrate surfacecomprising the dielectric material to form the electrical interconnect.

Removal of copper (or Ni or Co) from a substrate surface can be achievedby using chemical mechanical planarization. As described herein,chemical mechanical planarization can include application of a slurrysolution to a substrate surface using a polishing pad. A slurry solutioncan include chemical and mechanical components. For example, the slurrysolution can include abrasive particles to facilitate mechanicalremoval, as well as chemical components to facilitate chemical removalof the substrate surface material. For example, slurry solutions caninclude pH adjusting agents, oxidizing agents, catalysts and corrosioninhibiting agents.

Corrosion inhibiting agents can facilitate desired planarization byreducing undesired isotropic etching, dishing, erosion and/or corrosionof substrate surface materials during and/or after the chemicalmechanical planarization process. Benzotriazole (BTA) or anotherpassivation agent can be included in slurry solutions, for example as acorrosion inhibiting agent. The passivation agent can interact with thecopper (or Ni or Co) on the substrate surface to form a passivation filmon the surface of the copper. Without being limited by any particulartheory or mode of operation, benzotriazole or another passivation agentmay form a coordination complex with copper (or Ni or Co) to form acopper-containing polymeric passivation film during processing. However,the passivation film can remain on the surface of a copper layer afterchemical mechanical planarization is complete.

The presence of the passivation film after completion of chemicalmechanical planarization can undesirably change one or morecharacteristics of the substrate surface, thereby adversely affectingone or more subsequent fabrication processes (e.g., a selectivedeposition process). Thus, it is desirable to clean the passivation filmfrom the copper (or Ni or Co) surface so as to restore a cleaned coppersurface, while maintaining one or more characteristics of one or moreother materials on the substrate surface. For example, a substratesurface comprising elemental copper and a passivation film formedthereon may be subjected to the cleaning process to remove thepassivation film from the copper surface such that the substrate coppersurface is restored to the elemental copper state. In some embodiments,methods are provided for removal of the passivation film using a vaporphase reactant.

In some embodiments, methods described herein can be used to removemetal-containing particles from a substrate. In some embodiments, one ormore vapor phase reactants described herein can be used to remove themetal-containing particles. The metal-containing particles may have acomposition the same as or similar to a passivation film formed on themetal surface. For example, copper-containing particles may be generatedduring chemical mechanical planarization of a copper surface on asubstrate. The copper-containing particles may be formed over variousportions of the substrate surface, including over portions of thesubstrate surface which do not have copper. For example,copper-containing particles may be generated over dielectric material onthe substrate surface while polishing the substrate. Without beinglimited by any particular theory or mode of operation, the vapor phasereactant may interact with the copper-containing particles to reduce asize of the particles and/or form one or more volatile byproducts suchthat the smaller particles and/or the volatile byproducts can be removedfrom the substrate surface. Removal of the particles from the substratesurface may further facilitate restoration of one or more properties ofthe substrate surface. In some embodiments, removal of the particles mayprovide desired removal of passivation material from the substratesurface, for example providing desired selectivity for the passivationmaterial removal process. In some embodiments, methods described hereincan remove all or substantially all metal-containing particles from thesubstrate surface. In some embodiments, more than about 50% of themetal-containing particles are removed, including greater than about70%, or greater than about 90%.

In some embodiment, one or more substrate surface cleaning processesdescribed herein can remove from a substrate surface metal-containingparticles having a longest dimension of up to about 20 nm, up to about10 nm, up to about 5 nm, or up to about 2 nm.

Although discussed herein primarily in terms of removal of passivationfilms, the substrate surface cleaning processes may also be applied tosubstrate surfaces for removal of metal-containing particles.

In some embodiments, a substrate comprising a passivation film on atleast one surface, is contacted with a vapor phase reactant. Thepassivation film may have been formed by a chemical mechanicalplanarization process, such as by exposure to benzotriazole. In someembodiments a substrate comprising a copper film with a passivation filmformed thereon is contacted with a vapor phase reactant. In someembodiments, the vapor phase organic reactant comprises a vapor phaseorganic reducing agent. For example, the substrate surface passivationfilm may be exposed to an organic vapor phase reducing agent. Withoutbeing limited by any particular theory or mode of operation, the vaporphase organic reducing agent may react with, for example reduce, one ormore components of the passivation layer such that the passivation layercan be removed from the substrate surface, for example by formation ofvolatile byproducts which can be readily transported away from thesubstrate surface. Further without being limited by any particulartheory or mode of operation, copper on the substrate surface which hasbeen oxidized may be reduced by the vapor phase organic reducing agent.For example, the oxidized elemental copper may be reduced by the vaporphase organic reducing agent to a zero oxidation state such thatelemental copper is restored. In some embodiments, although referred toherein as a reducing agent, the vapor phase organic reducing agent mayfacilitate removal of the passivation film without or substantiallywithout effecting a reduction. The terms organic reducing agent orreducing agent do not limit the scope of the disclosure to processes inwhich a reduction is effected.

In some embodiments, a process for removing the passivation film caninclude a plurality of cycles. A cycle of the passivation film removalprocess may comprise contacting one or more vapor phase organicreactants with a desired substrate surface, for example a surface of thepassivation film. In some embodiments, one or more parameters of a cyclecan be different from that of another cycle. For example, selection ofone or more vapor phase reactants, a vapor phase reactant flow rate,reaction chamber pressure, process temperature, and/or duration of thecycle, may be different from that of another cycle. In some embodiments,the removal process includes a plurality of cycles where each cycle hassimilar or the same process conditions as that of other cycles in theprocess.

Removing the passivation film can include removing part or all of thepassivation film from a desired substrate surface. In some embodiments apassivation film is removed from the surface of a copper layer, whileadvantageously preserving surface characteristics of one or more othermaterials on the substrate surface. For example, one or more processesdescribed herein can be used to restore a copper surface by removing apassivation layer from the copper surface without, or substantiallywithout changing a surface chemistry of a dielectric material on thesubstrate surface. In some embodiments, exposure of the substratesurface to the organic reactant, such as formic acid, during thepassivation film removal process can reduce an oxidation state of thesubstrate surface copper to an oxidation state of zero such that thecopper is restored to an elemental copper state, providing an activatedcopper surface having desired catalytic activity for a subsequentfabrication process. For example, the copper surface may be activated bythe passivation film removal process such that it has desired catalyticactivity for a subsequent selective deposition process.

In some embodiments, one or more processes described herein do notcomprise a plasma process. In some embodiments, one or more processesdescribed herein comprise a thermal process. For example, one or morevapor phase organic reactants are not activated by a plasma source priorto their contact with the passivation film. In some embodiments, one ormore processes described herein are free or substantially free ofradicals. In some embodiments, a thermal process may provide removal ofa passivation film from a copper surface while avoiding or substantiallyavoiding adversely affecting one or more characteristics of one or moreother materials on the substrate surface, including one or morecharacteristics of a dielectric material (e.g., a low-k dielectricmaterial on the substrate surface exposed to the thermal process), suchthat a subsequent selective deposition process can selectively depositon the cleaned copper surface. In some embodiments, a thermal processmay not significantly remove or alter hydrophobic functional groups fromthe surface of the one or more other materials on the substrate (e.g.,—CH₃ groups on the surface of the low-k dielectric material), such thathydrophobicity of the one or more other materials is preserved orsubstantially preserved. In contrast, a plasma process may undesirablyaffect one or more characteristics of other materials on the substratesurface, such as the hydrophobicity of the materials (e.g.,hydrophobicity of low-k dielectric materials by removal of —CH₃ groupsfrom the surface of the low-k dielectric materials).

In some embodiments, the one or more other materials on the substratesurface can be pre-treated prior to exposing the substrate to the one ormore vapor phase reactants for removing the passivation film from thesubstrate. In some embodiments, the one or more other materials on thesubstrate surface can be pre-treated to reduce or inhibit subsequentdeposition of a conductive material on the material, such as depositionof a metal. For example, a dielectric material, such as a low-kdielectric material, can be pre-treated by contacting the dielectricmaterial with one or more pre-treatment reactants in a thermal vaporphase process to form a protective material on the dielectric material.Forming the protective material on the dielectric material prior toremoving the passivation film on the copper surface may facilitatedesired pre-treatment of the dielectric material without undesirablyaffecting properties of the copper surface. Without being limited by anyparticular theory or mode of operation, a thermal process for removingthe passivation film from the copper surface may not significantlyaffect one or more characteristics of the protective material formed onthe dielectric material, thereby facilitating retaining desiredproperties of the protective material and thus providing desiredsubsequent selective deposition on the cleaned copper surface.

In some embodiments, the one or more pre-treatment reactants are notliquid phase pre-treatment reactants. In some embodiments, the one ormore pre-treatment reactants are vapor phase pre-treatment reactants. Insome embodiments, the protective film is not formed by self-assembledmonolayers (SAM), for example hydrocarbons comprising long alkyl chainsas a backbone, such as alkyl chains having a length of C4 or higher, orC6 or higher.

In some embodiments, the pre-treatment reactant is one or more oftrimethylchlorosilane (CH₃)₃SiCl (TMCS), trimethyldimethylaminosilane(CH₃)₃SiN(CH₃)₂ or another type of alkyl substituted silane havingformula R_(4-x)SiX_(x), wherein x is from 1 to 3, preferably x is 1, andeach R can independently selected to be a C1-C5 hydrocarbon, such asmethyl, ethyl, propyl or butyl, preferably methyl, and X is halide or Xis another group capable of reacting with OH-groups, such as analkylamino group —NR₁R₂, wherein each R₁ can be independently selectedto be hydrogen or C1-C5 hydrocarbon, preferably methyl or ethyl, R₂ canbe independently selected to be C1-C5 hydrocarbon, preferably methyl orethyl, preferably X is chloride or dimethylamino. In some embodiments,the pre-treatment reactant can be a silane compound comprising at leastone alkylamino group, such as bis(diethylamino)silane, or a silanecompound comprising a SiH₃ group, or silazane, such hexamethyldisilazane(HMDS).

In some embodiments, selective deposition over the cleaned copper (or Nior Co) surface can be performed after removal of the passivation film.For example, one or more materials may be selectively deposited onto thecleaned surface without depositing on one or more other, differentmaterials on the substrate surface. As used herein, selective depositionof one or more materials over the cleaned copper surface comprisesdeposition of the one or more materials on and in direct contact withthe cleaned copper surface while less deposition, or even no deposition,occurs on a different material on the substrate. In some embodiments, anelectrically conductive material can be deposited on and in directcontact with the cleaned copper surface. In some embodiments, a metalcan be selectively deposited on and in direct contact with the cleanedcopper surface. In some embodiments, a noble metal can be selectivelydeposited on and in direct contact with the cleaned copper surface. Insome embodiments, the metal can be selectively deposited on and indirect contact with the cleaned copper surface using an atomic layerdeposition (ALD) process. For example, ALD type processes can be basedon controlled, self-limiting surface reactions of vapor phase precursorsin which gas phase reactions are avoided by alternately and sequentiallycontacting the substrate with the precursors by removing excessreactants and/or reactant byproducts from the reaction chamber betweenprecursor pulses. In some embodiments, the ALD process for depositingthe metal can include using a first precursor and a second precursor,where the first precursor comprises a metal precursor and the secondprecursor comprises a precursor which does not or substantially does notoxidize the cleaned copper surface.

In some embodiments, tungsten can be selectively deposited on and indirect contact with the cleaned copper surface. For example, thesubstrate surface may include a dielectric material such that tungstencan be selectively deposited over the cleaned copper surface, while noor substantially no tungsten is deposited on the dielectric material.

FIG. 1 shows an example of a substrate surface cleaning process 100 forremoving a passivation film formed over a copper layer. In block 102, asubstrate having a first surface comprising copper can be provided. Forexample, the substrate can be provided as part of an integrated circuitfabrication process. In block 104, the copper can be exposed tobenzotriazole thereby forming a passivation film on the surface of thesubstrate. For example, the copper may be exposed to benzotriazoleduring a CMP process. In block 106, the passivation film can becontacted with a vapor phase organic reactant to remove the passivationfilm. For example, the vapor phase organic reactant can react with thepassivation film to generate one or more volatile byproducts tofacilitate removal of the passivation film. In some embodiments, a purgestep can follow contacting the passivation film with the vapor phaseorganic reactant to remove excess reactants and/or reaction byproductsfrom the reaction chamber. In some embodiments, contacting thepassivation film with the vapor phase organic reactant can be repeated anumber of times. Contacting the passivation film with the vapor phaseorganic reactant may be repeated a plurality of times to facilitatedesired removal of the passivation film, and provide a cleaned coppersurface. For example, a substrate surface cleaning process may include aplurality of cycles, where each cycle includes contacting thepassivation film with a vapor phase organic reactant. In someembodiments, at least one of the plurality of cycles comprises a purgestep. For example, some cycles may not include a purge step. In someembodiments, each cycle comprises a purge step.

In some embodiments, contacting the passivation film with the vaporphase organic reactant is not repeated. For example, the substratesurface cleaning process may include a single continuous orsubstantially continuous duration in which the passivation film isexposed to the organic reactant.

In some embodiments, a substrate surface cleaning process can beperformed in a batch reaction chamber. In some embodiments, a substratesurface cleaning process can be performed in a single-wafer reactionchamber. Exemplary single wafer reactors are commercially available fromASM America, Inc. (Phoenix, Ariz.) under the tradenames Pulsar® 2000 andPulsar® 3000 and ASM Japan K.K (Tokyo, Japan) under the tradename Eagle®XP and XP8. Exemplary batch ALD reactors are commercially available fromand ASM Europe B.V (Almere, Netherlands) under the tradenames A400™ andA412™.

In some embodiments, a vapor phase organic reactant can be selectedbased on its ability to react with and remove the passivation film underdesired conditions, such as by reacting with the film to form volatilebyproducts. In some embodiments, the vapor phase organic reactant candemonstrate thermal stability within a range of process temperatures.For example, the vapor phase organic reactant may be thermally stableacross a desired range of process temperatures such thatgrowth-disturbing condensable phases do not form on the substrate and/orthe vapor phase organic reactant does not generate harmful levels ofimpurities on the substrate surface through thermal decomposition. Insome embodiments, the vapor phase organic reactant can exhibitsufficient vapor pressure such that a desired quantity of chemicalmolecules is present in the gas phase near the substrate surface toenable the reduction reactions.

In some embodiments, a vapor phase organic reactant may be selectedbased on its ability to decompose into two or more reactive components,at least one of which can react with the passivation film to form avolatile byproduct. For example, the vapor phase organic reactant maydesirably decompose under process conditions of one or more cycles ofthe substrate surface clean process such that one or more of thereactive components generated by the decomposition process may reactwith the passivation film. In some embodiments, both one or more of thedecomposed parts and the vapor phase organic reactant itself can reactwith passivation film.

In some embodiments, the vapor phase reactant comprises an organicreactant, such as formic acid. In some embodiments, the vapor phasereactant comprises acetic acid (CH₃COOH) and/or propanoic acid(CH₃CH₂COOH). In some embodiments, the organic reactant can include analcohol. In some embodiments, the organic reactant can include analdehyde. In some embodiments, the organic reactant can have at leastone functional group selected from the group consisting of alcohol(—OH), aldehyde (—CHO), and carboxylic acid (—COOH).

Without being limited by any particular theory or mode of operation, theprocess for eroding and/or removing the passivation film can includereducing one or more components of the passivation film by using theorganic reactant, such that at least a portion of the passivation filmcan be removed from the substrate surface. As described herein, thevapor phase reactant gas comprises an organic acid, including acarboxylic acid. Reaction between the passivation film and thecarboxylic acid can generate one or more volatile byproducts which canbe readily transported away from the substrate surface and removed fromthe reaction space. For example, the carboxylic acid may reduce oxidizedcopper forming part of the passivation film such that the oxidizedcopper may be restored to its elemental state.

In some embodiments, eroding and/or removing the passivation film maynot comprise reducing one or more components of the passivation film.For example, the organic reactant may interact with one or morecomponents of the passivation film to erode and/or remove the filmwithout or substantially without reducing any components of thepassivation film.

Reactants containing at least one alcohol group are preferably selectedfrom the group consisting of primary alcohols, secondary alcohols,tertiary alcohols, polyhydroxy alcohols, cyclic alcohols, aromaticalcohols, and other derivatives of alcohols.

Preferred primary alcohols have an —OH group attached to a carbon atomwhich is bonded to another carbon atom, in particular primary alcoholsaccording to the general formula (I):

R¹—OH  (I)

wherein R¹ is a linear or branched C₁-C₂₀ alkyl or alkenyl groups,preferably methyl, ethyl, propyl, butyl, pentyl or hexyl. Examples ofpreferred primary alcohols include methanol, ethanol, propanol, butanol,2-methyl propanol and 2-methyl butanol.

Preferred secondary alcohols have an —OH group attached to a carbon atomthat is bonded to two other carbon atoms. In particular, preferredsecondary alcohols have the general formula (II):

wherein each R¹ is selected independently from the group of linear orbranched C₁-C₂₀ alkyl and alkenyl groups, preferably methyl, ethyl,propyl, butyl, pentyl or hexyl. Examples of preferred secondary alcoholsinclude 2-propanol and 2-butanol.

Preferred tertiary alcohols have an —OH group attached to a carbon atomthat is bonded to three other carbon atoms. In particular, preferredtertiary alcohols have the general formula (III):

wherein each R¹ is selected independently from the group of linear orbranched C₁-C₂₀ alkyl and alkenyl groups, preferably methyl, ethyl,propyl, butyl, pentyl or hexyl. An example of a preferred tertiaryalcohol is tert-butanol.

Preferred polyhydroxy alcohols, such as diols and triols, have primary,secondary and/or tertiary alcohol groups as described above. Examples ofpreferred polyhydroxy alcohol are ethylene glycol and glycerol.

Preferred cyclic alcohols have an —OH group attached to at least onecarbon atom which is part of a ring of 1 to 10, more preferably 5-6carbon atoms.

Preferred aromatic alcohols have at least one —OH group attached eitherto a benzene ring or to a carbon atom in a side chain.

Preferred reactants containing at least one aldehyde group (—CHO) areselected from the group consisting of compounds having the generalformula (V), alkanedial compounds having the general formula (VI), andother derivatives of aldehydes.

Thus, in one embodiment preferred reactants are aldehydes having thegeneral formula (V):

R³—CHO  (V)

wherein R³ is selected from the group consisting of hydrogen and linearor branched C₁-C₂₀ alkyl and alkenyl groups, preferably methyl, ethyl,propyl, butyl, pentyl or hexyl. More preferably, R³ is selected from thegroup consisting of methyl or ethyl. Examples of preferred compoundsaccording to formula (V) are formaldehyde, acetaldehyde andbutyraldehyde.

In another embodiment preferred reactants are aldehydes having thegeneral formula (VI):

OHC—R⁴—CHO  (VI)

wherein R⁴ is a linear or branched C₁-C₂₀ saturated or unsaturatedhydrocarbon. Alternatively, the aldehyde groups may be directly bondedto each other (R⁴ is null).

Preferred reactants containing at least one —COOH group are preferablyselected from the group consisting of compounds of the general formula(VII), polycarboxylic acids, and other derivatives of carboxylic acids.

Thus, in one embodiment preferred reactants are carboxylic acids havingthe general formula (VII):

R⁵—COOH  (VII)

wherein R⁵ is hydrogen or linear or branched C₁-C₂₀ alkyl or alkenylgroup, preferably methyl, ethyl, propyl, butyl, pentyl or hexyl, morepreferably methyl or ethyl. In some embodiments, R⁵ is a linear orbranched C₁-C₃ alkyl or alkenyl group. Examples of preferred compoundsaccording to formula (VII) are formic acid, propanoic acid and aceticacid, most preferably formic acid (HCOOH).

In some embodiments, the reactant demonstrates desired vapor pressuresuch that the reactant can be volatized without heating the reactant. Insome embodiments, such a reactant comprises only one carboxyl group(—COOH). In some embodiments, such a reactant is not a dicarboxylicacid. In some embodiments, such a reactant is not a citric acid.

In some embodiments, the reactant can be heated to volatize the reactantprior to delivering the volatized reactant to the substrate surface. Insome embodiments, such a reactant comprises a dicarboxylic acid,including an oxalic acid.

In some embodiments, the reactant comprises less than about 15 weight %water (H₂O). Preferably, the reactant comprises less than about 5 weight% water, more preferably less than about 2 weight %, and most preferablyless than about 1 weight %. For example, the reactant may comprise lessthan about 0.5 weight % water.

As described herein, a reactant may decompose into two or more reactivecomponents during the substrate surface clean process. For example, someof the carboxylic acid delivered to a reaction space may decompose intocarbon monoxide (CO) and hydrogen gas (H₂) during the substrate surfaceclean process, such that one or more of the carbon monoxide (CO),hydrogen gas (H₂) and/or an undecomposed carboxylic acid reacts with thepassivation film to facilitate removal of the film. In this way asubstrate surface may be exposed to hydrogen gas (H₂) even though nohydrogen gas (H₂) is actively provided into the reaction space from anexternal source.

In some embodiments, the vapor phase organic reactant may be stored in aliquid phase and subsequently volatized prior to being delivered to thesubstrate surface. In some embodiments, the vapor phase organic reactantis in vapor phase in the reaction space such that the reaction space isfree or substantially free of any liquid phase reactants. For example,the vapor phase organic reactant may be in liquid phase during storageand may be subsequently volatized prior to delivery into a reactionchamber such that only or substantially only organic reactant in thevapor phase is present within the reaction chamber.

In some embodiments, a vapor phase reactant may be stored in a gasbubbler and can be supplied to the reaction chamber from the gasbubbler. In some embodiments, the vapor phase reactant can be stored ina gas bubbler at around room temperature (e.g., from about 20° C. toabout 25° C.). For example, the vapor phase reactant gas may be pulsedinto the reaction chamber from the gas bubbler during a cycle of thesubstrate surface cleaning process. In some embodiments, a mass flowrate of the vapor phase reactant may be controlled by controlling theextent to which a valve for delivering the vapor phase reactant into thereactor chamber is kept open (e.g., a needle valve). For example, a massflow rate may be selected such that a quantity of the vapor phasereactant may be flowed into the reaction chamber during a cycle of thecleaning process to facilitate desired removal of the passivation filmduring the cycle.

In some embodiments, a vapor phase reactant pulse can have a duration ofabout 0.5 second (s) to about 60 s, about 1 s to about 20 s, or about 1s to about 10 s. A duration of a cycle can be selected to providedesired quantity of the vapor phase reactant into the reaction space. Insome embodiments, a vapor phase reactant pulse comprises a duration ofabout 1 s. For example, a cycle of the substrate surface cleaningprocess comprises flowing formic acid (HCOOH) into the reaction spacefor a duration of about 1 s.

In some embodiments, a cycle of the substrate surface cleaning processcomprises flowing carrier gas into the reaction space. For example, thecarrier gas may be flowed during a vapor phase reactant pulse. Thecarrier gas may comprise one or more inert gases. In some embodiments,the carrier gas comprises one or more of nitrogen gas (N₂), argon (Ar),and helium (He). For example, the carrier gas may facilitate transportof the vapor phase reactants to the substrate surface and/or transportaway from the substrate surface one or more byproducts generated by thereaction between the vapor phase reactants and the substrate surfacepassivation film. In some embodiments, the carrier gas can facilitatereaction between the one or more vapor phase reactants and the substratesurface passivation film without or substantially without itselfreacting with the passivation film. In some embodiments, a carrier gasmay be flowed through a gas bubbler for storing the vapor phase reactantprior to being delivered to the reaction chamber to facilitate deliveryof the vapor phase reactant to the reaction chamber.

In some embodiments, a cycle of the substrate surface cleaning processmay not include actively flowing hydrogen gas (H₂) into the reactionspace. For example, hydrogen gas may be generated within the reactionspace due to one or more reactions occurring in the reaction space eventhough hydrogen gas is not actively provided into the reaction spacefrom an external source.

In some embodiments, a substrate surface cleaning process can includemultiple distinct durations in which the passivation film is exposed toone or more vapor phase reactants. For example, the substrate surfacecleaning process may include exposing the passivation film to aplurality of vapor phase reactant pulses. In some embodiments, asubstrate surface cleaning process can include one single continuous orsubstantially continuous duration in which the passivation film isexposed to one or more vapor phase reactants. For example, the substratesurface cleaning process may include exposing the passivation film to asingle vapor phase reactant pulse. For example, a duration of the singlevapor phase reactant pulse may be selected to remove all orsubstantially all of the passivation film.

In some embodiments, exposing the passivation film to one or more vaporphase reactants can be followed by an interval in which the one or morevapor phase reactants are not actively provided into the reactionchamber. For example, the substrate may be transported from the reactionspace to a space in which it is not exposed or substantially not exposedto the one or more vapor phase reactants during the interval. In someembodiments, a purge step can be performed during the interval tofacilitate removal of one or more excess reactants and/or reactionbyproducts from the reaction chamber. A purge step may include flow ofinert gas through the reaction chamber and/or evacuation of the reactionchamber (e.g., by drawing a vacuum upon the reaction chamber), tofacilitate removal of excess reactants and/or reaction byproducts. Insome embodiments, both transport of the substrate and the purge step canbe performed during an interval. In some embodiments, the substrate isnot transported and remains in the reaction space during the purge step.

In some embodiments, an interval follows each period of exposing thepassivation film to the one or more vapor phase reactants. In someembodiments, a purge step and/or transport of the substrate follow eachexposure of the passivation film to the one or more vapor phasereactants. For example, subsequent to each exposure of the substrate tothe vapor phase reactant(s) in each cycle, the substrate may be moved toa space free or substantially free of the vapor phase reactants, or thereaction chamber may be purged of excess reactants and/or reactionbyproducts. In some embodiments, the purge step comprises continuingflow of the carrier gas (e.g., continuing flow of the carrier gas, suchas at least one component of a multi-component carrier gas, at a same ordifferent flow rate as compared to that during the reactant pulse). Forexample, a substrate surface cleaning process may include continuouslyflowing the carrier gas while periodically flowing the one or more vaporphase reactants. For example, the substrate surface cleaning process mayinclude continuous flow of nitrogen gas (N₂) while periodically flowingvapor phase formic acid.

In some embodiments, an interval following a contacting the passivationfilm with one or more vapor phase reactants for cleaning the substratesurface can have a duration of about 1 s to about 360 s, including aboutis to about 120 s, including about 1 s to about 60 s. In someembodiments, a purge step can be performed for the duration of theinterval. For example, a purge step can have a duration of about 1 s toabout 360 s, including about is to about 120 s, including about 1 s toabout 60 s. In some embodiments, a purge step after contacting thepassivation film with one or more vapor phase reactants can have aduration of about 30 s, about 20 s, or about 10 s. In some embodiments,one or more parameters of a purge step can be different from that ofanother purge step in a substrate surface cleaning process comprising aplurality of purge steps. For example, one or more purge steps betweentwo reactant pulses may have a duration shorter than that of a purgestep following a last reactant pulse of the substrate surface cleanprocess. For example, one or more purge steps between two reactantpulses may have an inert gas flow rate lower than that of a purge stepfollowing a last reactant pulse. In some embodiments, a substratesurface cleaning process may include one or more intervals in which apurge step is not performed. For example, a purge step may be performedfollowing only some reactant pulses of a substrate surface cleanprocess.

Flow rate of one or more inert gases during a purge step can be selectedto provide desired purging of the reaction chamber. In some embodiments,the purge step can include flow of up to about 2,000 standard cubiccentimeters per minute (sccm) of an inert gas, including about 50 sccmto about 1,500 sccm, or about 100 sccm to about 1,000 sccm. For example,a purge step may comprise flow of nitrogen gas (N₂) at 1000 sccm for aduration of about 10 s.

In some embodiments, the substrate surface cleaning process does notinclude an interval between two reactant pulses. For example, theprocess may include exposing the substrate surface to a single reactantpulse configured to provide the desired amount of reactants to thesubstrate surface.

In some embodiments, a cycle of the substrate surface cleaning processcan be performed at a process temperature of about 50° C. to about 500°C., preferably from about 100° C. to about 400° C., and more preferablyfrom about 150° C. to about 350° C. For example, the process temperaturemay be about 200° C. to about 300° C. The process temperature asreferred to herein can comprise a temperature of a reaction chambersusceptor, a reaction chamber wall, and/or a temperature of thesubstrate itself. For example, a temperature of the substrate may beselected to facilitate reaction between the substrate surfacepassivation film and the one or more vapor phase reactants, and/orfacilitate generation of volatile byproducts during each cycle of thesubstrate surface clean process, while maintaining the substrate at atemperature to reduce or avoid overheating of the substrate and/ordamage to one or more substrate features. In some embodiments, a processtemperature of a cycle of the substrate surface cleaning process can beabout 200° C. to about 250° C. For example, the substrate may be heatedto a temperature of about 200° C. to about 250° C. during one or morecycles of the substrate surface clean process.

In some embodiments, the pressure of the reactor chamber duringprocessing is maintained at about 0.01 Torr to about 760 Torr,preferably from about 0.1 Torr to about 50 Torr, and more preferablyabout 0.1 Torr to about 10 Torr. In some embodiments, a cycle of thesubstrate surface cleaning process can be performed with a reactionchamber pressure of about 0.5 Torr to about 3 Torr. For example, thechamber pressure may be about 1 Torr to about 2 Torr, including about1.5 Torr. The selected reaction chamber pressure may serve to facilitatedesired removal of the passivation film.

As described herein, a substrate surface cleaning process can include aplurality of cycles comprising exposing a surface passivation film toone or more vapor phase reactants. A number of cycles of the substratesurface cleaning process may be selected to facilitate desired removalof the passivation film. In some embodiments, a number of cycles of thesubstrate surface cleaning process may depend on one or more parametersof the substrate surface cleaning process. For example, a number ofcycles may depend on a process temperature of one or more cycles of theprocess, for example, a relatively lower number of cycles may beselected for a process which includes one or more cycles comprising arelatively higher process temperature. In some embodiments, thesubstrate surface cleaning process comprises up to about 100 cycles,including up to about 50 cycles. In some embodiments, the processcomprises about 10 cycles. In some embodiments, a total number ofcycles, and/or process conditions of one or more cycles of the process,can be selected to achieve complete removal of the passivation film,without or substantially without damaging the copper.

In some embodiments, one or more parameters of a cycle of a substratesurface cleaning process can be different from that of another cycle.For example, selection of one or more vapor phase reactants, a vaporphase reactant flow rate, chamber pressure, process temperature, and/orduration of the cycle, may be different from that of another cycle. Insome embodiments, the cleaning process includes a plurality of cycles,each cycle having similar or the same process conditions as that ofother cycles in the process.

Referring to FIG. 2, another example of a substrate surface cleaningprocess 200 is shown for removing a passivation film, such as apassivation film formed over a copper layer. In block 202, a substratehaving a surface comprising copper can be provided. In block 204,chemical mechanical planarization can be performed upon the copper usingbenzotriazole, where exposing the copper to the benzotriazole forms apassivation film on the surface of the substrate. In block 206, thepassivation film can be removed from the surface by contacting thepassivation film with a vapor phase organic reactant to obtain a cleanedcopper surface. In block 208, a second material can be selectivelydeposited on the cleaned copper surface. For example, the secondmaterial may be deposited on the cleaned surface of the copper layerwithout or substantially without depositing on one or more othermaterials on the substrate surface. In some embodiments, tungsten can beselectively deposited on the cleaned copper surface.

In some embodiments, a substrate comprising a passivation film formed ona surface can be subjected to a surface cleaning process. The substratesurface can include a dielectric material (e.g., a dielectric materialhaving a k value of about 2.3, or an extreme low-k material (ELK 2.3dielectric material)). The surface cleaning process can includecontacting the passivation film with one or more pulses of vapor phaseformic acid. In some embodiments the surface cleaning process caninclude 10 repetitions of contacting the passivation film with formicacid, where each repetition can have a duration of about 10 s. Forexample, the formic acid can be supplied to the reaction chamber for theduration of each repetition. The formic acid can be maintained in a gasbubbler at around room temperature (e.g., at a temperature of about 20°C. to about 25° C.) and provided to the reaction chamber from the gasbubbler during each cycle of the cleaning process. A process temperaturefor each of the cycles can be about 200° C. to about 250° C. Forexample, a temperature of the substrate was maintained at a temperatureof about 200° C. during each of the cycles. Each cycle of the cleaningprocess had a chamber pressure of about 0.5 Torr to about 3 Torr. Apurge step can be performed following each repetition of contacting thepassivation film with formic acid. According to some embodiments, atungsten film can be subsequently selectively deposited directly ontothe cleaned copper surface. No or substantially no tungsten wasdeposited on the dielectric material on the substrate surface.

As described herein, one or more processes described herein canfacilitate desired removal of the passivation film while preserving oneor more characteristics of one or more other materials on the substratesurface. In some embodiments, surface characteristics of the materialson the substrate surface can be analyzed using contact anglemeasurements. For example, contact angle analysis can be used to analyzesurface chemistry of one or more materials on the substrate surface.Contact angle analysis of a substrate surface can be measured both priorto and subsequent to performing a substrate surface cleaning processsuch that characteristics of the surface before initiating the substratesurface cleaning process can be compared with characteristics of thesubstrate surface after completion of the substrate surface cleaningprocess. In some embodiments, water contact angle analysis can indicatechange or preservation of a surface chemistry. Contact angle analysiscan measure wettability of the surface of a material. In someembodiments, water can be used as a probing liquid for water contactangle measurements to determine the hydrophobicity or hydrophilicity ofthe material surface. The angle at which a water and vapor (e.g., air)interface meets the material surface can be measured. For example,contact angle can decrease as tendency of a drop of water to spread outover a surface increases, providing an inverse measure of wettability ofthe surface. A contact angle of less than about 90° can indicate asurface favorable to being wetted (e.g., hydrophilic) and a contactangle greater than 90° can indicate that the surface is not favorable tobeing wetted (e.g., hydrophobic). For example, a copper surface, such asa clean copper surface free or substantially free of a passivation film,can be hydrophilic (e.g., demonstrating a water contact angle of lessthan about 90°), and a low-k dielectric surface can be hydrophobic(e.g., demonstrating a water contact angle of greater than 90°). In someembodiments, the sessile drop technique can applied to determine watercontact angle measurements for a surface, for example using a contactangle goniometer.

Example

A substrate comprising a passivation film formed on a surface wassubjected to a surface cleaning process, according to one or moreembodiments described herein. The passivation film was formed over acopper layer on a surface, due to reaction of the copper layer andbenzotriazole. The substrate surface also included a dielectric material(e.g., a dielectric material having a k value of about 2.3, or anextreme low-k material (ELK 2.3 dielectric material)). The cleaningprocess facilitated removal of the passivation film such that a cleanedcopper surface was provided. The cleaned copper surface comprisedrestored elemental copper. The surface cleaning process included 10repetitions of contacting the passivation film with a vapor phasereactant, where each repetition had a duration of about 10 s. A purgestep was performed following each repetition of contacting thepassivation film with a vapor phase reactant. The vapor phase reactantof the surface clean process included formic acid. For example, vaporphase formic acid was flowed into the reaction chamber during each ofthe repetitions. The formic acid was maintained in a gas bubbler ataround room temperature (e.g., at a temperature of about 20° C. to about25° C.) and was provided to the reaction chamber from the gas bubbler.For example, a supply valve for providing the formic acid into thereaction chamber was kept open to an extent to facilitate desired supplyof the formic acid. Vapor phase formic acid was provided from the gasbubbler into the reaction chamber for the duration of each repetition. Aprocess temperature for each of the repetition was about 200° C. Forexample, a temperature of the substrate was maintained at a temperatureof about 200° C. during each of the repetitions. Each repetition of thecleaning process had a chamber pressure of about 0.5 Torr to about 3Torr, for example about 1.5 Torr.

The substrate comprising the cleaned copper surface was subsequentlysubjected to a selective deposition process. A tungsten film wassubsequently selectively deposited directly onto the cleaned coppersurface. No or substantially no tungsten was deposited on the dielectricmaterial on the substrate surface.

Water contact angle analyses were performed on surfaces of thepassivation film, the cleaned copper surface (e.g., after removal of thepassivation film), and the dielectric material prior to and subsequentto the surface cleaning process. Water contact angle of the passivationfilm was measured prior to the surface cleaning process and wasdetermined to be about 90°, indicating for example that the surface ofthe passivation film is hydrophobic. Water contact angle of the cleanedcopper substrate surface was measured after completion of the surfacecleaning process (e.g., water contact angle of the surface over whichthe passivation film was previously present) was measured and wasdetermined to be about 30°, indicating a change of the surface frombeing hydrophobic to being hydrophilic after the surface cleaningprocess. Water contact angle of a surface of the dielectric film on thesubstrate surface was measured prior to initiating the substrate surfacecleaning process and was determined to be above about 90°. Water contactangle of a surface of the dielectric film was measured after completionof the 10-cycle substrate surface cleaning process and was determined tobe above 90°, remaining unchanged or substantially unchanged from thevalue measured prior to the start of the substrate cleaning process.Without being limited by any particular theory or mode of operation, thewater contact angle analysis of the passivation film, the cleaned coppersurface, and the dielectric material can indicate that the cleaningprocess facilitated desired removal of the passivation film, restoring asurface chemistry of the copper layer, while maintaining the surfacechemistry of the dielectric material on the substrate. Maintaining thesurface chemistry of the substrate surface may advantageously facilitatesubsequent processing of the substrate, including for example, selectivedeposition onto the cleaned copper substrate surface.

Although this disclosure has been provided in the context of certainembodiments and examples, it will be understood by those skilled in theart that the disclosure extends beyond the specifically describedembodiments to other alternative embodiments and/or uses of theembodiments and obvious modifications and equivalents thereof. Inaddition, while several variations of the embodiments of the disclosurehave been shown and described in detail, other modifications, which arewithin the scope of this disclosure, will be readily apparent to thoseof skill in the art based upon this disclosure. It is also contemplatedthat various combinations or sub-combinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the disclosure. It should be understood that various featuresand aspects of the disclosed embodiments can be combined with, orsubstituted for, one another in order to form varying modes of theembodiments of the disclosure. Thus, it is intended that the scope ofthe disclosure should not be limited by the particular embodimentsdescribed above.

The headings provided herein, if any, are for convenience only and donot necessarily affect the scope or meaning of the devices and methodsdisclosed herein.

1. (canceled)
 2. A method for removing at least a portion of apassivation film from a substrate surface, the method comprising:exposing the passivation film to a vapor phase organic reactant that isan alcohol, an aldehyde or has the formula R—COOH, where R is hydrogenor a C1 to C3 alkyl, wherein the passivation film was formed by exposureof a metal surface on the substrate to a passivation agent comprising ahydrocarbon, and wherein the passivation film is not exposed to a plasmaduring exposure of the passivation film to the vapor phase organicreactant.
 3. The method of claim 2, wherein the passivation film isexposed to the vapor phase organic reactant at a temperature of 100° C.to 400° C.
 4. The method of claim 2, wherein the vapor phase organicreactant comprises carboxylic acid.
 5. The method of claim 2, whereinthe vapor phase organic reactant comprises formic acid.
 6. The method ofclaim 2, wherein the passivation agent comprises an aromatichydrocarbon.
 7. The method of claim 2, wherein the passivation agentcomprises benzotriazole.
 8. The method of claim 2, further comprisingrepeating exposing the passivation film to the vapor phase organicreactant at least 10 times.
 9. The method of claim 2, wherein the metalsurface is a copper surface.
 10. The method of claim 2, wherein thesubstrate surface further comprises a dielectric material, and wherein asurface chemistry of the dielectric material is substantially unaffectedby exposing the passivation film to the vapor phase organic reactant.11. A method of removing copper-containing particles from a substratesurface, comprising: contacting a substrate surface comprisingcopper-containing particles with a vapor phase organic reactant withoutexposing the substrate to a plasma, such that copper-containingparticles are removed from the surface.
 12. The method of claim 11,wherein the substrate comprises a copper surface that has been subjectto chemical mechanical polishing prior to contacting the substratesurface with the vapor phase organic reducing agent.
 13. The method ofclaim 11, wherein the copper-containing particles are removed from asubstrate surface that does not otherwise comprise copper.
 14. Themethod of claim 11, wherein the substrate surface comprisingcopper-containing particles is a dielectric surface.
 15. The method ofclaim 11, wherein the vapor phase organic reactant is an alcohol, analdehyde, or has the formula R—COOH, where R is hydrogen, a C1 to C3alkyl.
 16. The method of claim 15, wherein the vapor phase organicreactant comprises a carboxylic acid.
 17. The method of claim 15,wherein the vapor phase organic reactant comprises formic acid.
 18. Themethod of claim 11, wherein the substrate surface is contacted with thevapor phase organic reactant at a temperature of 100° C. to 400° C. 19.The method of claim 11, wherein greater than 70% of the coppercontaining particles are removed from the substrate surface.
 20. Themethod of claim 11, wherein the copper-containing particles have alongest dimension of up to about 20 nm.
 21. The method of claim 11,wherein the copper-containing particles form a passivation layer on thesubstrate surface prior to contacting the substrate surface with thevapor-phase organic reactant.